In Case Of Difficulty - Kenwood TS-790A Instruction Manual

6-4. IN CASE OF DIFFICULTY
The problems described in this table are failures
caused in general by improper operation or connec-
tion of the transceiver, not by defective components.
RECEPTION
Examine and check according to the following table.
If the problem persists, contact an authorized agent
or service station.
Symptom
Probable cause
Corrective action
Nothing is displayed or wrong digits are
displayed when the POWER switch is
turned on.
3. Power supply is OFF.
1. Bad power cable or connections.
2. Blown power supply fuse.
1. Check cables and connections.
. Check for the cause of the blown
fuse and replace the fuse.
The microprocessor may maifunction if
the input voltage is too low.
1. Use a step-up transformer to raise
the line voltage. Use a 12 Vto 16 V
battery.
2. Turn on the POWER switch while
depressing the A=B (or A/B) key,
and then release the A=B {or A/B}
key.
No signal is received even when the an-
tenna is connected or the receiving sen-
sitivity is low.
1, SQL control fully clockwise.
2. The ATT switch is ON.
3. Microphone PTT switch is in
transmit position.
the
1. Turn the SQL control counter-
clockwise.
Set the ATT switch off.
Set the PTT switch to the receive po- .
sition.
2.
3.
An antenna is connected, but no signal
| is received and the 'S-meter fully
| deflects.
! The S-meter deflects and stays at a cer-
tain position even with no signal.
Low AC line voltage.
Use a step-up transformer to raise the
line voltage.Use a 12 V to 16 V battery.
-|
Signal is received, but no sound is
heard.
MODE key position is incorrect.
Change the MODE key to the correct |
mode.
: SSB received signal is extremely high
cut or low cut.
IF SHIFT control is wrong adjusted.
| Set the control to the center (click po-
sition).
ene |
_ Frequency is not changed by pressing
; the UP/DOWN switches, turning the
| TUNING knob.
F. LOCK key is ON.
Set F. LOCK key to OFF.
| Memory scan fails.
Nothing is stored in memory.
; Display goes out with VFO/M ON.
When nothing is stored in the memory i
channel, a channel is displayed and
blanked with only the decimal point dis-
played.
Store the frequency.
SUB indicator remains OFF, and the
desired frequency can not be selected.
MAIN and SUB bands are set to the ;
same frequency. i
Push the SUB key to select another
|
|
|
! |
|
band. ;
TRANSMIT
Symptom
Probable cause
Corrective action
Output
. Microphone jack is not plugged in. |
. Poor antenna connection.
. Plug jack in.
| In CW, pressing the key does not cause
transmission.
hs
. Key jack is not plugged in.
. Poor key contact.
. Plug jack in.
1
2. Connect antenna securely.
1
2. Clean contact.
station does not answer.
In USB, LSB, CW, AM, or FM the called |
RIT causes send and receive frequen-
cy mismatch.
Press RIT switch to exit RIT mode.
64